Decorative wall covering

ABSTRACT

A decorative wall covering comprising a paper sheet having a decorative surface which has a continuous coating of a polymeric material thereon, the paper sheet being laminated on its other surface to an open weave fabric whereby the tendency of the covering to curl on wetting with a water-based adhesive is reduced.

United States Patent 1 1 Burton 1 51 Feb. 6, 1973 1 DECORATIVE WALLCOVERING [75] Inventor: Arthur Burton, Denton, England [73] Assignee:Imperial Chemical Industries,

Limited, London, England [22] Filed: Feb. 22, 1971 [21] Appl. No.:117,700

[56] References Cited UNlTED STATES PATENTS Miller et a1. ..161/413 XStone ct a1 ..161/220 X 3,547,767 12/1970 Keeling et a1 161/41 3 X1,193,060 8/1916 Rasmussen ..16l/82 2,274,851 3/1942 Schneider ..161/822,683,094 7/1954 Jones et a1. ...16l/250 X 3,041,222 6/1962 Malmquist..161/249 X FOREIGN PATENTS OR APPLICATIONS 880,318 10/1961 GreatBritain ..161/82 Primary ExaminerWilliam A. Powell Attorney-Cushman,Darby & Cushman [57] ABSTRACT A decorative wall covering comprising apaper sheet having a decorative surface which has a continuous coatingof a polymeric material thereon, the paper sheet being laminated on itsother surface to an open weave fabric whereby the tendency of thecovering to curl on wetting with a water-based adhesive is reduced.

5 Claims, N0 Drawings DECORATIVE WALL COVERING This invention relates toa decorative wallcovering comprising a sheet of paper coated on one ofits surfaces, its decorative surface, with a coating of a polymericmaterial such as polyvinyl chloride or polyethylene.

The term sheet of paper" should be construed to include not only thepaper sheets used hitherto as wallcovering materials but also websmainly of cellulosic fibers impregnated or bonded with a synthetic resinor a rubber latex or other bonding agent.

A disadvantage is that when it is wetted by a water based adhesive thepaper absorbs water from the adhesive which causes it to swell andexpand. The resistance of the polymeric coating to expansion produces acurl in a transverse direction in the material and when the wallcoveringis hung on a wall the longitudinal edges of the material lift away fromthe wall. This makes it difficult and time consuming to hang thewallcovering. Latex impregnated papers are particularly prone toexpansion and are known to expand as much as 2 percent or more whenfully wetted.

When a soft polymeric coating, for example a plasticized polyvinylchloride coating composition containing 50 or more parts of plasticizerper 100 parts of polyvinyl chloride, of less than about 0.003 inchthickness is used the coating appears to have sufficient stretch toexpand with the expanding wet paper without introducing an objectionablecurl in the product. This is especially so when the effective thicknessand rigidity of the coating is reduced by providing the coating with anembossed pattern. However, we have found that when the plasticizedpolymeric coating has a thickness in excess of about 0.003 inch, itcannot adapt itself to the change in dimensions of the wetted paper andin resisting the tendency of the paper to expand causes the product tocurl when adhesive is applied.

When the polymeric coating is unplasticized or has a lower plasticizercontent than above, the tendency to curl is pronounced even when thecoating thickness is less than 0.003 inch and even when it is less than0.001 inch. This, of course, places an undesirable restriction on thevariety and quality of non-curling polymeric coated papers which can beproduced.

We have now found that the tendency ofa polymeric coated paper to curlwhen the paper is wetted by a water based adhesive can be reduced bylaminating to the free surface of the paper a fabric which will balancethe polymeric coating in resisting the tendency of the paper to expandwhen wetted. The fabric therefore serves as a relatively non-extensiblemesh which resists curling when the paper is wetted.

ln accordance, therefore, with our invention we provide a decorativewallcovering comprising a paper sheet having on one of its surfaces acontinuous coating of a polymeric material and laminated to its othersurface a fabric.

The fabric is permeable to water but essentially, like the polymericcoating, should not be prone toswellingwhen wetted by the water basedadhesive.

Conveniently we laminate the fabric to the free surface of the paper bymeans of an adhesive. The fabric may be laminated to the paper eitherbefore or after the paper has been provided with a polymeric coating.Though any suitable adhesive may be used, particularly suitableadhesives are those based on nitrile rubber.

Preferably the fabric is of open weave and a particularly suitablefabric of our invention is a scrim fabric. By scrim fabric" we means alow-quality plain cloth of the muslin type with cover factors for bothwarp and weft of about 4. The weight per unit area of the fabric variesaccording to the fiber used but it is usually between 0.5 and 2 ounces,per square yard when the fabric is made from cotton. The term coverfactor means ratio of threads per inch to the square root of the yarncount. For example, a cover factor of 28 indicates that the area iscovered by threads laid side by side in contact giving percent coverage:hence a cover factor of 4 indicates about one-seventh coverage.

It will be appreciated that by treating the surface of the paper in theway we propose we will not be prevented from using any of theconventional water based adhesive since a large area of surface of thecoated paper will still be accessible. Further, uniform wetting andswelling of the fibers in the paper is not prevented because theadhesive can readily penetrate through and beneath the fabric.

The mechanism of our anti-curl treatment appears to be the two sidedresistance to the expanding paper fibers provided by the plasticized orunplasticized polymeric coating and the fabric, which although notreducing the amount of expansion significantly reduces or eliminates thecurl by providing balanced forces on each side of the paper.

The wallcovering according to the present invention may conveniently bein the form of rolls of sheet material. The rolls can be provided in avariety of widths depending on the country in which the wallcoveringwill be sold. In this country the rolls will commonly be provided in awidth of about 21 inches. In a number of European countries the rollswill be required to have a width of 55 cms. to meet local requirements.

Our invention will now be further illustrated by the following example:

EXAMPLE A sample of a wallcovering product consisting of a latexsaturated paper having an approximately 0.005 inch coating ofplasticized and pigmented polyvinyl chloride, the plasticizer contentbeing 50 parts per hundred parts of resin, was prepared. This productwas decorated by printing and embossing in accordance with conventionaltechniques.

Subsequently a water based starch adhesive was applied to the freesurface of the paper and an attempt was made to attach the product toa.wall. This was not satisfactory because of excessive curling whichcaused the longitudinal edges of the wallcovering to lift away from thewall.

Two pieces of the product prepared as above were now laminated throughthe medium of a nitrile rubber adhesive to:

1. A scrim fabric having a yarn count of 44 X 54 c.c. and weighing 0.75ounces/square yard; and having 28 ends per inch X 22 picks per inch and2. A scrim fabric having a yarn count of 44 X 44 c.c. and weighing 1.7ounces/square yard, and having 58 ends 2. A scrim fabric having a yarncount of 44 X 44 c.c. and weighing 1.7 ounces/square yard, and having 58ends per inch X 48 picks per inch.

After the laminating adhesive has set, a water based starch adhesive wasapplied to the fabric/paper surface of each piece. Neither piece curledand it could easily and quickly be attached to the wall.

What is claimed is:

l. A decorative wall covering comprising a paper sheet having adecorative surface which has a cntinuous coating of a polymeric materialthereon, said paper sheet being laminated on its other surface to anopen weave fabric whereby the tendency of said covering to curl onwetting with a water-based adhesive is reduced.

2. A decorative wallcovering as claimed in claim 1 in which thepolymeric material is unplasticized.

3. A decorative wallcovering as claimed in claim 1 in which thepolymeric material is plasticized polyvinyl chloride, the coating havinga thickness in excess of 0.003 inch.

4. A wall covering as claimed in claim 1 wherein said fabric is a scrimfabric having a cover factor for both warp and weft of about 4 andweighing between 0.5 and 2 ounces per square inch.

5. A Wall covering as claimed in claim 4 wherein said fabric is bondedto said paper by means of a nitrile rubber adhesive and said polymericmaterial is polyvinyl chloride.

1. A decorative wall covering comprising a paper sheet having adecorative surface which has a continuous coating of a polymericmaterial thereon, said paper sheet being laminated on its other surfaceto an open weave fabric whereby the tendency of said covering to curl onwetting with a water-based adhesive is reduced.
 2. A decorativewallcovering as claimed in claim 1 in which the polymeric material isunplasticized.
 3. A decorative wallcovering as claimed in claim 1 inwhich the polymeric material is plasticized polyvinyl chloride, thecoating having a thickness in excess of 0.003 inch.
 4. A wall coveringas claimed in claim 1 wherein said fabric is a scrim fabric having acover factor for both warp and weft of about 4 and weighing between 0.5and 2 ounces per square inch.